| | | DIY Home Built Motorized Bicycle (non kit) Post all about your home built rides here. Weedwacker motors, lawn mower engines ect. This area is for non kit builds | Friction Drives Discussion at Motorized Bicycle Engine Kit Forum in the DIY Home Built Motorized Bicycle (non kit) forum. HI TO ALL, I THINK I FIGURED POSTING OUT!! I JUST MADE 2 OTHERS BUT THINK THEY ARE BURIED.. I ...  | | 
06-15-2008, 06:11 PM
| | Master Motorized Bicycle Builder | | Join Date: May 2008 Location: PENSACOLA, FL
Posts: 190
| | Friction Drives HI TO ALL, I THINK I FIGURED POSTING OUT!! I JUST MADE 2 OTHERS BUT THINK THEY ARE BURIED.. I DON`T SEE MUCH POSTED ABOUT FRICTION DRIVES. I BOUGHT MY FIRST CYCLE IN 1955, 1936 HARLEY 80 CUBIC IN. FLATHEAD. I WASN`T AWARE HOW FAR THE MOTOR BIKES HAVE CAME UNTIL THE FIRST OF THIS MONTH.  I ENJOY THE FORUM. VERY HELPFUL !! LATER GUYS, RON  | 
06-15-2008, 06:44 PM
|  | Master Motorized Bicycle Builder | | Join Date: Jan 2008 Location: north carolina
Posts: 3,061
| | Re: Friction Drives I like friction drive but not a lot of others seem to be as enthused as I. | 
06-15-2008, 11:01 PM
|  | Moderator | | Join Date: Mar 2008 Location: Tucson,Arizona
Posts: 1,791
| | Re: Friction Drives I'm planning a friction drive with a 33cc motor on a MTB. Deacon has inspired me.  | 
06-16-2008, 12:28 AM
|  | Master Motorized Bicycle Builder | | Join Date: Jan 2008 Location: Nor*Cal
Posts: 525
| | Re: Friction Drives I've ran a friction drive stand-up scooter for years. The only negative thing I didn't like was I was constantly getting flats. The spindle would drive whatever (thorns, nails, staples or glass) was stuck in the tire deeper. But besides that I was happy to own a 44 mph scooter.  | 
06-16-2008, 01:55 AM
| | Senior Motorized Bicycle Builder | | Join Date: Mar 2008
Posts: 54
| | Re: Friction Drives I am gonna go that way. and I have been thinking about it for months
__________________ Quote:
Originally Posted by sisdavid ya, we can ghost pedal by the man  | | 
06-16-2008, 05:22 AM
|  | Master Motorized Bicycle Builder | | Join Date: Jan 2008 Location: north carolina
Posts: 3,061
| | Re: Friction Drives If you don't have any serious hills to climb a 33cc friction drive should be cool. My lil 25cc does great on flat and minor hills but put it on a real hill and it just cant do the trick.
I am thinking seriously and I even bid (I lost thank god) on a chainsaw motor from ebay. I think I can use it with the clutch and sprocket to drive a rear wheel china sprocket. Something about 42cc is what I have in mind. I keep hoping someone can tell me what it will do so I don't have to wander into it. lol.
I just had a thought, I wonder since the chain saw motor is so light, how it would do as a front wheel drive with that china sprocket. Why I would do that I have no clue. Just a random thought from an electron misfire in my damaged brain no doubt.
But I do love friction drive. It is the easiest way to get power to the wheel. I never had the flat problems just the moisture problems. Standing water on the road will give me a sudden but temporary loss of power. Riding in the rain is a no no, but then why would anyone want to. | 
06-16-2008, 08:55 AM
| | Master Motorized Bicycle Builder | | Join Date: May 2008 Location: PENSACOLA, FL
Posts: 190
| | Re: Friction Drives Decon I Said Friction Drive, Its Real, No Fiction !!  JUST KIDDING YOU, AUTHOR. | 
06-17-2008, 10:14 AM
| | Senior Motorized Bicycle Builder | | Join Date: Mar 2008
Posts: 54
| | Re: Friction Drives Thanks deacon, I was wondering about how much displacement was enough. 33cc is enough then thats great. The larger stuff is a bit more expensive.
I have been keeping a close eye on your project, because I have been wanting to do the same thing. I also share the same concerns for the front wheel drive, but I think it might be unlikely to throw you forward because of the wheel spinning away from the forks when the bike is moving forward. I was also wondering how the steering might be affected by the extra weight.
Finding an engine thats adequate for a front wheel drive set up might be the hardest part though.
__________________ Quote:
Originally Posted by sisdavid ya, we can ghost pedal by the man  | | 
06-19-2008, 06:42 PM
|  | Master Motorized Bicycle Builder | | Join Date: Jan 2008 Location: north carolina
Posts: 3,061
| | Re: Friction Drives I mounted mine on the front for a day. It seemed to do okay but I just couldn't get all the stuff juggled right.
I think now I have the ideal solution for me at least.
1. The engine always stays in good contact with the rear wheel.
2. I pedal it down my short drive in full choke.
3. I switch to half choke for half a block after it starts.
4. I turn off the choke and just pedal away.
5. At about four miles an hour it will start.
6. It will shut down automatically when it slows below that speed. (If you have good constant pressure on the wheel.
7. I can start pedaling from a reasonable uphill and have it start no problem much better than even the china girl bike. It is much lighter. Now there is more drag on the rear wheel so it is harder to pedal than the bike would be without the engine but it is doable.
Downside:
You can not just pedal it. the engine will start. I will be carrying a tool kit to take the nuts off the engine hold down to release it. That is just in case of major problem far from home. I'll just tie the engine up and go.
I am still in the test phase but I learned something new today. Even the 25cc which I had no previous experience with has a threaded shaft. It was hidden behind a spacer of some kind. I found the when the spacer unscrewed itself for me by accident. I am now having a new drive wheel welded.
Also I found out that almost all new home improvement store trimmers have the same engine. the two hundred dollar trimmer has a 31cc ryobi engine and so does the 69.99 model.
If you live in a reasonably flat area the 31cc should take you all over the place no sweat. So even if you go new its 75 bucks for the engine another 75 or so for a wallymart bike and a little more for assembly parts, and you have a motorized bike.
I know even here I can get a working 31cc engine at the flea market for 35 bucks and a used bike for 25 bucks. Twenty five more for mounting hardware and for under a hundred bucks you are riding to work instead of walking.
When I am finished with this experimental project, I plan to do a parts list and step by step to convert a weed whacker to bike engine instructions.
If you have hills like me you might take a look at used backpack blower engines. Some of those run 40cc and of course chainsaws
Last edited by deacon : 06-19-2008 at 06:47 PM.
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06-20-2008, 12:20 AM
| | Senior Motorized Bicycle Builder | | Join Date: Mar 2008
Posts: 54
| | Re: Friction Drives Thanks for the information Deacon! I am staying tuned.
__________________ Quote:
Originally Posted by sisdavid ya, we can ghost pedal by the man  | | | Thread Tools | | | | Display Modes | Linear Mode |
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